Safety device



J. A. JONAS SAFETY DEVICE Nov. 19, 1935.

' Filed Dec.

INVE TOR wfl ATTO 7 rue Patented Nov. 19, 1935 UNITED STATES PATENTOFFICE 3 Claims.

This invention relates to an electrically controlled device forexhausting liquid from a storage tank and, more particularly, to asafety device for opening the electrical circuit when the liquid in thetank has fallen below a critical point.

I have described my invention herein in connection with a tank forstoring a volatile, electrically non-conducting liquid such as oil, andhave provided electrically controlled means for removing water settlingto the bottom of the tank. The control means comprises a circuitincluding two electrodes positioned adjacent the bottom of the tank,across which a circuit is closed when the water in the tank rises intocontact with said electrodes. While there is oil on top of the water inthe tank, there is little danger arising from any sparking which mayoccur at the electrodes when a circuit thereacross is either made orbroken. However, as is well known, if a volatile liquid such, forexample, as gasoline is exhausted from the tank, leaving fumes therein,the danger of explosion due to such sparking is very great. Suchsparking may occur, for example, due to dirt or any foreign matterdeposited on the electrodes. In order to avoid this dangerous conditionand prevent the explosive fumes from coming in contact with the saidelectrodes, I have provided a means controlled by the level of theliquid in the tank to break the said electric circuit Whenever theliquid in the tank falls below a predetermined point.

Other objects and advantages of the invention will appear from thefollowing description and the claims appended thereto, and the inventionmay best be understood if the description is read in connection with theaccompanying drawing, in which:

Fig. 1 is a vertical cross-section of a tank equipped with my device;and

Fig. 2 is a detail view on an enlarged scale of a contact switch.

As illustrated herein, the storage tank I is provided with a mainoutletpipe 2 for withdrawing oil from the tank, the orifice of which ispositioned somewhat above the bottom of the tank and the outlet 3,preferably positioned at the bottom of the tank, through which watercollecting in the tank may be withdrawn. The outlet passage 3 iscontrolled by the outlet valve 4 normally maintained in closed positionby the spring 5.

Depending through an aperture in the top of the tank I is a shaft 6adjacent the lower end of which is mounted an adjustable spacing member1, the position of which on the shaft 6 may be adjusted by means of anadjusting screw 8 to position the end of the shaft 6 at the desireddistance from the bottom of the tank I. Depending from the bottom of theshaft 6 are the two electrodes 9a and 9b, the upper ends of which 5 areconnected respectively to the wires I0 and I I contained within theshaft 6. The wire I 0 extends through the upper end of the shaft 6 tothe source of power I2. The wire II is connected at its upper end to themetal sleeve I3 surrounding 10 the upper end of the shaft I5, sleeve I3also contacting with the arm I4 of the contact switch I 5, carrying thetwov contacts I 5a and I5b.

At its top, tank I has an externally threaded lip portion 20 adapted toreceive the internally 15 threaded collar 2I surrounding the shaft 6.Mounted on the collar 2I is an upright 22, having pivotally mountedthereon the arm 23 which, in raised position, is adapted to close acircuit across the contacts I5a and I5b. Extending zo around the shaft 6is a sleeve 24 having at its lower end a float 25 and at its upper endthe finger 26 extending through the hollow boss 21 carried by the collar2|. The finger 26 normally contacts with the arm 23, maintaining thesaid 25 arm in raised position and thus closing the circuit across thecontacts I5a and IE1).

It will be apparent, that, due to the action of the float 25, the finger26, carried by the arm 24, will be pressed against the arm 23 until thewith- 80 drawal of liquid from the tank causes the float 25, carryingthe shaft 24 and the finger 26, to fall, thereby permitting the arm 23to fall and opening the circuit' across the contacts I511 and I517. 35

The contact I5a is connected to the frame I4, which is, in turn, incontact with the wire II through the contact switch I5. The contact I5!)is connected by the wire 28 with one end of the coil 29, the other endof which is connected ton-0 source of power I2 through the wire III. Thevalve 4 is mounted upon one end of a core or stem 30, the other end ofwhich is positioned within the coil 29, and when a circuit is passedthrough said coil, core 30 and the valve 4 are 45 drawn downwardlyagainst the action of spring 5, thereby opening the outlet 3 andpermitting water collecting in the bottom of the tank I to be drawn off.As soon as the electrical circuit is broken, the valve 4 is restored bythe spring 5 50 to close the exhaust passage 3.

When the water level in the tank rises so that the Water is in contactwith the electrodes 9a and 9b, the circuit is closed, permitting currentto flow from the source of power I2 through the wire ID to coil 29, wire28, contact I51) and through the water to electrode 9a and the wire Illback to the source of power l2. If, however, the liquid in the tank I islowered below a predetermined point, the float 25 and sleeve 24 willmove downwardly, thereby withdrawing finger 26 from the support of thearm 23 and breaking the circuit across the contacts 15a and I5b, therebyremoving all danger of sparking of the electrodes, regardless of thepresence of water in the bottom of the tank.

In order to test whether the device is functioning properly, separatehand operated means may be provided for closing the circuit, actuatingthe core stem 30, thereby opening the valve 4.

The making and breaking of the contact both indicate the liquid level,and both canv be made to operate a signal by well understood means, thusgiving notice of the level of the liquid in the tank.

What I claim is:

1. Inv combination with a liquid storage tank having an outlet and avalve controlling said outletQelectrically operated means for openingsaid valve, a shaft extending into said tank, a pair of spacedelectrodes carried by said shaft and connections between said electrodesand said electrically operated means, a switch intermediate said meansand said electrodes, a float in said tank, control means for saidswitch, and means interconnecting said float and said control means.

2. In combination with a liquid storage tank having an outlet and avalve controlling said outlet, electrically operated means for openingsaid valve, a shaft extending into said tank, a pair of spacedelectrodes carried by said shaft, extension members adjustably securedto said shaft, and extending below said electrodes, connections betweensaid electrodes and said electrically operated means, a switchintermediate said means and said electrodes having a pivoted contactarm, a float in said tank, and support means for said arm controlled bythe position of said float in said tank.

3. In combination with a liquid storage tank having an outlet and avalve controlling said outlet, electrically operated means for openingsaid valve, a pair of spaced electrodes in said tank, connectionsbetween said electrodes and said electrically operated means, a switchinter-'- rnediate said means and. said electrodes, afloat in said tank,and means interconnecting said float and said switch.

JAMES A. JONAS.

